| Message ID | 20190525014522.8042-2-jhubbard@nvidia.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v2] infiniband/mm: convert put_page() to put_user_page*() | expand |
On Fri, May 24, 2019 at 06:45:22PM -0700, john.hubbard@gmail.com wrote: > For infiniband code that retains pages via get_user_pages*(), > release those pages via the new put_user_page(), or > put_user_pages*(), instead of put_page() I have no objection to this particular patch, but ... > This is a tiny part of the second step of fixing the problem described > in [1]. The steps are: > > 1) Provide put_user_page*() routines, intended to be used > for releasing pages that were pinned via get_user_pages*(). > > 2) Convert all of the call sites for get_user_pages*(), to > invoke put_user_page*(), instead of put_page(). This involves dozens of > call sites, and will take some time. > > 3) After (2) is complete, use get_user_pages*() and put_user_page*() to > implement tracking of these pages. This tracking will be separate from > the existing struct page refcounting. > > 4) Use the tracking and identification of these pages, to implement > special handling (especially in writeback paths) when the pages are > backed by a filesystem. Again, [1] provides details as to why that is > desirable. I thought we agreed at LSFMM that the future is a new get_user_bvec() / put_user_bvec(). This is largely going to touch the same places as step 2 in your list above. Is it worth doing step 2? One of the advantages of put_user_bvec() is that it would be quite easy to miss a conversion from put_page() to put_user_page(), but it'll be a type error to miss a conversion from put_page() to put_user_bvec().
On Sun, May 26, 2019 at 04:06:31AM -0700, Matthew Wilcox wrote: > I thought we agreed at LSFMM that the future is a new get_user_bvec() > / put_user_bvec(). This is largely going to touch the same places as > step 2 in your list above. Is it worth doing step 2? > > One of the advantages of put_user_bvec() is that it would be quite easy > to miss a conversion from put_page() to put_user_page(), but it'll be > a type error to miss a conversion from put_page() to put_user_bvec(). FYI, I've got a prototype for get_user_pages_bvec. I'll post a RFC series in a few days.
On Sun, May 26, 2019 at 04:06:31AM -0700, Matthew Wilcox wrote: > On Fri, May 24, 2019 at 06:45:22PM -0700, john.hubbard@gmail.com wrote: > > For infiniband code that retains pages via get_user_pages*(), > > release those pages via the new put_user_page(), or > > put_user_pages*(), instead of put_page() > > I have no objection to this particular patch, but ... > > > This is a tiny part of the second step of fixing the problem described > > in [1]. The steps are: > > > > 1) Provide put_user_page*() routines, intended to be used > > for releasing pages that were pinned via get_user_pages*(). > > > > 2) Convert all of the call sites for get_user_pages*(), to > > invoke put_user_page*(), instead of put_page(). This involves dozens of > > call sites, and will take some time. > > > > 3) After (2) is complete, use get_user_pages*() and put_user_page*() to > > implement tracking of these pages. This tracking will be separate from > > the existing struct page refcounting. > > > > 4) Use the tracking and identification of these pages, to implement > > special handling (especially in writeback paths) when the pages are > > backed by a filesystem. Again, [1] provides details as to why that is > > desirable. > > I thought we agreed at LSFMM that the future is a new get_user_bvec() > / put_user_bvec(). This is largely going to touch the same places as > step 2 in your list above. Is it worth doing step 2? I think so, as these two conversions can run in parallel, whichever we finish first, biovec or put_user_pages lets John progress to step #3 Jason
On Fri, May 24, 2019 at 06:45:22PM -0700, john.hubbard@gmail.com wrote: > From: John Hubbard <jhubbard@nvidia.com> > > For infiniband code that retains pages via get_user_pages*(), > release those pages via the new put_user_page(), or > put_user_pages*(), instead of put_page() > > This is a tiny part of the second step of fixing the problem described > in [1]. The steps are: > > 1) Provide put_user_page*() routines, intended to be used > for releasing pages that were pinned via get_user_pages*(). > > 2) Convert all of the call sites for get_user_pages*(), to > invoke put_user_page*(), instead of put_page(). This involves dozens of > call sites, and will take some time. > > 3) After (2) is complete, use get_user_pages*() and put_user_page*() to > implement tracking of these pages. This tracking will be separate from > the existing struct page refcounting. > > 4) Use the tracking and identification of these pages, to implement > special handling (especially in writeback paths) when the pages are > backed by a filesystem. Again, [1] provides details as to why that is > desirable. > > [1] https://lwn.net/Articles/753027/ : "The Trouble with get_user_pages()" > > Cc: Doug Ledford <dledford@redhat.com> > Cc: Jason Gunthorpe <jgg@ziepe.ca> > Cc: Mike Marciniszyn <mike.marciniszyn@intel.com> > Cc: Dennis Dalessandro <dennis.dalessandro@intel.com> > Cc: Christian Benvenuti <benve@cisco.com> > > Reviewed-by: Jan Kara <jack@suse.cz> > Reviewed-by: Dennis Dalessandro <dennis.dalessandro@intel.com> > Reviewed-by: Ira Weiny <ira.weiny@intel.com> > Reviewed-by: Jérôme Glisse <jglisse@redhat.com> > Acked-by: Jason Gunthorpe <jgg@mellanox.com> > Tested-by: Ira Weiny <ira.weiny@intel.com> > Signed-off-by: John Hubbard <jhubbard@nvidia.com> > --- > drivers/infiniband/core/umem.c | 7 ++++--- > drivers/infiniband/core/umem_odp.c | 10 +++++----- > drivers/infiniband/hw/hfi1/user_pages.c | 11 ++++------- > drivers/infiniband/hw/mthca/mthca_memfree.c | 6 +++--- > drivers/infiniband/hw/qib/qib_user_pages.c | 11 ++++------- > drivers/infiniband/hw/qib/qib_user_sdma.c | 6 +++--- > drivers/infiniband/hw/usnic/usnic_uiom.c | 7 ++++--- > 7 files changed, 27 insertions(+), 31 deletions(-) Applied to for-next, thanks Jason
diff --git a/drivers/infiniband/core/umem.c b/drivers/infiniband/core/umem.c index e7ea819fcb11..673f0d240b3e 100644 --- a/drivers/infiniband/core/umem.c +++ b/drivers/infiniband/core/umem.c @@ -54,9 +54,10 @@ static void __ib_umem_release(struct ib_device *dev, struct ib_umem *umem, int d for_each_sg_page(umem->sg_head.sgl, &sg_iter, umem->sg_nents, 0) { page = sg_page_iter_page(&sg_iter); - if (!PageDirty(page) && umem->writable && dirty) - set_page_dirty_lock(page); - put_page(page); + if (umem->writable && dirty) + put_user_pages_dirty_lock(&page, 1); + else + put_user_page(page); } sg_free_table(&umem->sg_head); diff --git a/drivers/infiniband/core/umem_odp.c b/drivers/infiniband/core/umem_odp.c index f962b5bbfa40..17e46df3990a 100644 --- a/drivers/infiniband/core/umem_odp.c +++ b/drivers/infiniband/core/umem_odp.c @@ -487,7 +487,7 @@ void ib_umem_odp_release(struct ib_umem_odp *umem_odp) * The function returns -EFAULT if the DMA mapping operation fails. It returns * -EAGAIN if a concurrent invalidation prevents us from updating the page. * - * The page is released via put_page even if the operation failed. For + * The page is released via put_user_page even if the operation failed. For * on-demand pinning, the page is released whenever it isn't stored in the * umem. */ @@ -536,7 +536,7 @@ static int ib_umem_odp_map_dma_single_page( } out: - put_page(page); + put_user_page(page); if (remove_existing_mapping) { ib_umem_notifier_start_account(umem_odp); @@ -659,7 +659,7 @@ int ib_umem_odp_map_dma_pages(struct ib_umem_odp *umem_odp, u64 user_virt, ret = -EFAULT; break; } - put_page(local_page_list[j]); + put_user_page(local_page_list[j]); continue; } @@ -686,8 +686,8 @@ int ib_umem_odp_map_dma_pages(struct ib_umem_odp *umem_odp, u64 user_virt, * ib_umem_odp_map_dma_single_page(). */ if (npages - (j + 1) > 0) - release_pages(&local_page_list[j+1], - npages - (j + 1)); + put_user_pages(&local_page_list[j+1], + npages - (j + 1)); break; } } diff --git a/drivers/infiniband/hw/hfi1/user_pages.c b/drivers/infiniband/hw/hfi1/user_pages.c index 02eee8eff1db..b89a9b9aef7a 100644 --- a/drivers/infiniband/hw/hfi1/user_pages.c +++ b/drivers/infiniband/hw/hfi1/user_pages.c @@ -118,13 +118,10 @@ int hfi1_acquire_user_pages(struct mm_struct *mm, unsigned long vaddr, size_t np void hfi1_release_user_pages(struct mm_struct *mm, struct page **p, size_t npages, bool dirty) { - size_t i; - - for (i = 0; i < npages; i++) { - if (dirty) - set_page_dirty_lock(p[i]); - put_page(p[i]); - } + if (dirty) + put_user_pages_dirty_lock(p, npages); + else + put_user_pages(p, npages); if (mm) { /* during close after signal, mm can be NULL */ atomic64_sub(npages, &mm->pinned_vm); diff --git a/drivers/infiniband/hw/mthca/mthca_memfree.c b/drivers/infiniband/hw/mthca/mthca_memfree.c index 8ff0e90d7564..edccfd6e178f 100644 --- a/drivers/infiniband/hw/mthca/mthca_memfree.c +++ b/drivers/infiniband/hw/mthca/mthca_memfree.c @@ -482,7 +482,7 @@ int mthca_map_user_db(struct mthca_dev *dev, struct mthca_uar *uar, ret = pci_map_sg(dev->pdev, &db_tab->page[i].mem, 1, PCI_DMA_TODEVICE); if (ret < 0) { - put_page(pages[0]); + put_user_page(pages[0]); goto out; } @@ -490,7 +490,7 @@ int mthca_map_user_db(struct mthca_dev *dev, struct mthca_uar *uar, mthca_uarc_virt(dev, uar, i)); if (ret) { pci_unmap_sg(dev->pdev, &db_tab->page[i].mem, 1, PCI_DMA_TODEVICE); - put_page(sg_page(&db_tab->page[i].mem)); + put_user_page(sg_page(&db_tab->page[i].mem)); goto out; } @@ -556,7 +556,7 @@ void mthca_cleanup_user_db_tab(struct mthca_dev *dev, struct mthca_uar *uar, if (db_tab->page[i].uvirt) { mthca_UNMAP_ICM(dev, mthca_uarc_virt(dev, uar, i), 1); pci_unmap_sg(dev->pdev, &db_tab->page[i].mem, 1, PCI_DMA_TODEVICE); - put_page(sg_page(&db_tab->page[i].mem)); + put_user_page(sg_page(&db_tab->page[i].mem)); } } diff --git a/drivers/infiniband/hw/qib/qib_user_pages.c b/drivers/infiniband/hw/qib/qib_user_pages.c index f712fb7fa82f..bfbfbb7e0ff4 100644 --- a/drivers/infiniband/hw/qib/qib_user_pages.c +++ b/drivers/infiniband/hw/qib/qib_user_pages.c @@ -40,13 +40,10 @@ static void __qib_release_user_pages(struct page **p, size_t num_pages, int dirty) { - size_t i; - - for (i = 0; i < num_pages; i++) { - if (dirty) - set_page_dirty_lock(p[i]); - put_page(p[i]); - } + if (dirty) + put_user_pages_dirty_lock(p, num_pages); + else + put_user_pages(p, num_pages); } /** diff --git a/drivers/infiniband/hw/qib/qib_user_sdma.c b/drivers/infiniband/hw/qib/qib_user_sdma.c index 0c204776263f..ac5bdb02144f 100644 --- a/drivers/infiniband/hw/qib/qib_user_sdma.c +++ b/drivers/infiniband/hw/qib/qib_user_sdma.c @@ -317,7 +317,7 @@ static int qib_user_sdma_page_to_frags(const struct qib_devdata *dd, * the caller can ignore this page. */ if (put) { - put_page(page); + put_user_page(page); } else { /* coalesce case */ kunmap(page); @@ -631,7 +631,7 @@ static void qib_user_sdma_free_pkt_frag(struct device *dev, kunmap(pkt->addr[i].page); if (pkt->addr[i].put_page) - put_page(pkt->addr[i].page); + put_user_page(pkt->addr[i].page); else __free_page(pkt->addr[i].page); } else if (pkt->addr[i].kvaddr) { @@ -706,7 +706,7 @@ static int qib_user_sdma_pin_pages(const struct qib_devdata *dd, /* if error, return all pages not managed by pkt */ free_pages: while (i < j) - put_page(pages[i++]); + put_user_page(pages[i++]); done: return ret; diff --git a/drivers/infiniband/hw/usnic/usnic_uiom.c b/drivers/infiniband/hw/usnic/usnic_uiom.c index e312f522a66d..0b0237d41613 100644 --- a/drivers/infiniband/hw/usnic/usnic_uiom.c +++ b/drivers/infiniband/hw/usnic/usnic_uiom.c @@ -75,9 +75,10 @@ static void usnic_uiom_put_pages(struct list_head *chunk_list, int dirty) for_each_sg(chunk->page_list, sg, chunk->nents, i) { page = sg_page(sg); pa = sg_phys(sg); - if (!PageDirty(page) && dirty) - set_page_dirty_lock(page); - put_page(page); + if (dirty) + put_user_pages_dirty_lock(&page, 1); + else + put_user_page(page); usnic_dbg("pa: %pa\n", &pa); } kfree(chunk);